10.40.3 Can you answer these questions?

10.40.3.1 Exact value of a trig angle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=308989

Is there a way I can get an exact value (in terms of radicals) for Cos[74Degree] ? 
I tried: 
 FunctionExpand[Cos[74 Degree]] 
 
... 
[trigonometry]
 

asked by Steve237 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69429 Score of 2

10.40.3.2 Mathematica produces the diagonal minors in reverse order? Why?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=308975

For the matrix 
 L={{-k31-k32,k13,k23},{k31,-k12-k13,k21},{k32,k12,-k21-k23}}; 
 
Mathematica produces the reverse 
... 
[matrix] [linear-algebra]
 

asked by florin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54979 Score of 1

10.40.3.3 How can I make PlotMarkers overlap with opacity?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=309124

I want to render a TimelinePlot of events. But the events are so dense that they may overlap. 
For exmaple something like: 
... 
[plotting] [rendering] [marker] [timeline]
 

asked by user1747134 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53378 Score of 1

answered by JimB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19758 Score of 0